A mistake was present in an earlier version of the review article ‘RTX Adhesins are Key Bacterial Surface Megaproteins in the Formation of Biofilms’ by Guo et al. The last two sentences of the section 'Cell-Surface Retention Region: A Calcium-Independent Plug Anchors the Adhesin in the T1SS OMP' were 'Intriguingly, although the β-sandwich plug is conserved in the non-RTX adhesin of P. aeruginosa (CdrA), it lacks the T(P)-A-A-G site for proteolysis. Instead, CdrA is retained by a “cysteine hook” that restricts its secretion through the outer-membrane pore [80,81].' This text should read 'Intriguingly, although a T-A-A-G site for proteolysis is present in the non-RTX adhesin of P. aeruginosa (CdrA), this protein is retained by a ‘cysteine hook’ that restricts its secretion through the outer-membrane pore via the Type Vb secretion system [80,81].' This has now been corrected.